Crankshaft balancer



Jan 117, 195G MCMASTER 2,4945%9 CRANKSHAFT BALANCER Filed NOV. 19, 1947 2 shets-sheeb l III II II II II II llllll IN VEN TOR.

A'ITDRNEYS Fan, 17, 1950 E MCMASTER 2,4945% CRANKSHAFT BALANCER Filed Nov. 19, 1947 2 Sheets-Sheet 2 ENTOR.

{award Maa-zer BY I". fiww ATTEI RN EYE Patented Jan. 1 7, 1956 PATENT OFFICE GRANKSHAFT BALANGER Edward: McMaster, Sandwich; 111-, Application November 19, 1947; s-ei-iai- No; 787,012

My present" invention relatesto an: improved crankshaft balancer-ofi the-type especially adapt ed for use when grinding" or otherwisereinforc'-- ing the worncrankpl-ns of 'a' crank shaft.

Normally in truelng or" grinding a connecting rod bearing on a crankshaft, the crankshaft and holders: therefor are badly unbalanced with the result that a perfect grinding" cannot be had.

The device of my invention will overcome this difiicul'ty; and permit a: perfect grinding oper ation.

In the" accompanying" drawings, 1- have illus trated" one complete example ofthe physical embodiment of my invention; according to-thebest mode 1? have thus far devised, but it will be understood that various changes and alterations maybe made in" the exemplified structure within theseope of the" appended claims.

'In the drawings:

Figure 1 is a sideelevational view-ofa crankshaft in a" grinding tool' support:

Figure 2 is' arr elevational' View of" one" bearing biock;

Figure 3 isaside elevational vi-ew of theblock with the-securing or clampbl'ock removed:

Figure 4'- is-a sectional viewat line 4 2 of Figure 2;

Figure" 5 is a- View of" the clamp block;

Figure 6 is a. bottom plan View of the device showing both drive pins engaged;

Figure. '7 is. a front elevational: view" of. the: balance device;

Figure 8.-isan elevational- View. of. the balance device with the cooperating head plate shown in dotted lines;

, Figure 9" is a bottom view of the device'simrlar to Figure 6 with parts removed;

Figure 10 is an elevational View of a modified bearing block for thecrankshaft a guidingtool support;

Figure 11 is an-elevational viewofthe modified block, per se;

Figure 12 is a sectional view on the line l2-l2 of Figure 11;

Figure 13 is an enlarged sectional view on the line I 3| 3 of Figure 11;

Figure 14 is an elevational view similar to Figure 7 of a modified form of balance device;

Figure 15 is a sectional view on the line l5| 5 of Figure 14;

Figure 16 is a bottom view of Figure 14 and Figure 17 is a perspective view of a modified form of balance weight.

Referring now to the drawings, and more especially to Figures 1 to 9, inclusive, wherein I have ill'us-trateds one form of the embodiment of my chine, the head having a gear 22 driven by'suita- 1 ble means t0' rotate the crankshaft 23 so that the offset cranks 2 1 and 25 respectively may be separately rotated against the grinding wheel 26-.

Bearing blocks: 2 have bearingcups or center blocks 28 and 29 having the central conical shaped sockets 33- for receipt ofthe center pins 31 and 3'Z respectively oi' the headand tail stock or the grinding machine. block secifions are secured by bolts 33 in the recesses 3'4 inone side of the-blocks Z1 intermediate ofthe cups 2'8 and 2 9 respectively. The block and clampsection" assembly respectively having openings 35" formedby diametrically opposed recesses t fi to olamp onto theend's 31 oi' the shaft 23. Secured to the head plate 38, bymeans ofscrews'at; is a circular cent'erbored plate 40, which is of the same" configuration as the head plate 38 The screws 39 are spaced along a transverse center of theplate M; and onone sideof this center, adjacent the" periphery of the plate 6 0', there are removably mounted, the diametrically opposed drive pi'ns 4 F and 42- respectively; These" pins engage on oppositesites of thebearihg block ZF to rotate" the shaft 23-.

To offset the tendency of the" pins 4i and 42 to throw the plate ill off balance, a weight- 43 is securedtc-theplate'w'on theopposite side of the center; adjacent the periphery'of'the-plate lib-by bolts 44-, to balance the-pins and the crankshaft and holders therefor; In bothinstances, the heads of the screws and the heads of the bolts 4d are countersunk within the face of the plate- 41 and the Weight 43% 45, is a balancing weight 41% which is-use'dto balance the crankshaft and its assembly so that when rotating the shaft, a perfect" grinding is obtained. This weight being used when a lot of stock must be removed from the crankshaft. The weight can be disconnected after the excess stock has been removed, still leaving the crank and holders perfectly balanced. Therefore, before grinding the crankshaft 23, the assembly, including the shaft and the bearing blocks, is adjusted so that the cups 28 or 29 will be used, which most nearly conforms to the axis of rotation through the crankshaft 23.

With the assembly mounted as in Figure 1, and the head stocks 2!) rotating, the pins 4! and 42 will engage the block 2'1 and cause the shaft 23 Removable clamp to rotate against the wheel 26 in perfect balance, thereby obtaining a perfectly rounded siuface at the cranks 29 and respectively. As previously stated, the weight it is used to obtain the perfect balance of the shaft.

In Figures 10 to 17, inclusive, there is shown a modified form of my invention in use with a crankshaft which is dissimilar in shape to the crankshaft 23.

The crank 50 has the cranks 5i and 52 respectively lying in the same plane with an offset crank 53, and the ends 54 of the crank 50 are mounted as later described.

The modified form of bearing block 55 is in the form of an equilateral triangle having rounded apexes 56 and, mounted at each apex, is a bearin cup or center block 5?, having the conical shaped center sockets 58 for receipt of the center pins 3! and 32 of the head and tail stock of the grinding machine.

- Formed on the face of the block 55 in upstanding relation thereto, centrally of the cups 51', are the projections 59, the use of which will be later described.

At the center of the block 55, there is provided a semi-circular recess 6%, confronting a similar recess iii in a clamp block 52, and these recesses form the opening 652 which engage the ends of the crank 50.

The block 82 is slidably mounted in the cutout 63, in the block 55. Guide plates 64 secured by screws 65 to both faces of the block 55 on opposite sides of the cutout 93 in overlapping relation to the clamp block 62 retain this block in the cutout 93. block 55, at right angles thereto, enters the cutout 53 to engage the clamp block 62, whereby the block is forced into clamping position on the end 54 of the crank 50.

The center bored plate ET is similar in shape to plate 40, but the screws 58 securing this plate to the head plate 38 are on the vertical center line of the plate. The drive pins 69 and i0 therefor are reniovably mounted on the plate 6! 0n opposite sides of the center line adjacent the lower peripheral edge of the plate. These pins engage the projections 59 on opposite sides thereof to rotate the shaft, as previously described. A Weight 'H is secured to the plate 67 in similar manner as is the weight 33, and the screws 12 are on opposite sides of the center, as defined by the screws 68. A balancing weight 13, similar to the weight 46, is secured to the weight H by a bolt "M for the same purpose, as the weight 46.

Should a larger crank be used, and a heavier balancing weight be desired, the weight 14 shown in Figure '7 having openings for two bolts to fasten it to the weights 48 or H is used, the opening 15 aligning with the bolts used to secure the latter weights to their respective plates.

The operation of this form of the invention is similar to the operation of the form shown in Figures 1 to 9, inclusive.

A bolt 6% entering the edge of the i There is thus provided a device for automatically balancing a crankshaft during the grindin thereof, eliminating the use of counterweights on the crankshaft or holder blocks, eliminating having to shift weights during the grinding of the crankshaft, and eliminating having to shift or move the crank or holders therefor.

It is believed that the foregoing description will clearly point out to those skilled in the art, the construction and manner of use of the device, and it is to be understood that changes in the minor details of construction, arrangement and combination of parts may be resorted to, provided they fall within the spirit of the invention and the scope of the appended claims.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The combination with a lathe having a head stock and a tail stock each of which is provided with a center pin to receive a crankshaft to be ground, of a pair of bearing blocks each of which is provided with a central opening therein to receive an end of the crankshaft, removably mounted bearing cups at the ends of said blocks to eccentrically receive said center pins, a balance plate secured to the head stock, a pair of relatively spaced eccentric drive pins on said plate adapted to have operational engagement with said blocks for the rotation thereof a weight on said plate in opposed relation to said pins to counterbalance the pins and the blocks and a detachable weight on the first weight to counterbalance the crankshaft.

2. The invention as in claim 1 wherein said bearing blocks are rectangular in shape having a centrally located recess in one side thereof to receive a clamp section whereby said blocks are fixed to said crankshaft and the drive pins are adapted to engage the opposite sides of said block.

3. The invention as in claim 1 wherein said bearing blocks are triangular in shape having an adjustable clamp block therein to engage said crankshaft to retain said block on said crankshaft and projections are provided on one face of said block centrally of each side thereof to engage the drive pins on said plate.

. EDWARD McMASTE REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Healy Oct. 28, 1947 

